Process and apparatus for electroplating



W. E. BELKE.

PROCESS AND APPARATUS FOR ELECTROPLATING. APPLICAUON FILED MARA l5l1922.

l ,426y 1 4 1 Paiend Aug. 15, 1922.

"done -be kept open when in use, so that the work unirse stares"ege-Tsar serios.

WILLIAM BELKE, 0F CHICAGO, IL LINOIS.

PROCESS AND .APPARATUS FOeR EIECTROPLTNG.

Specification of Letters Patent.

Patented Aug. 15, 1922.

Application lcd March 15, 19,22. Serial No. 543,889.

To all 'whom t may concern Be it known that I, WILLIAM E. BELKE, acitizenof the United States, and a resident of Chicago, Cook County,Illinois, have invented a certain new and useful Improve-- ment inProcesses and Apparatus for Electroplating, of which the following is aspecification.

This invention relates to electroplating in general, and moreparticularly to methods or processes of this kind in which a tank orother receptacle is provided for the electroplating solution in whichthe work is Obviously, a tank of this kind must `therefore, quite liableto interfere very seriously with the efficiency of the electroplatingapparatus, and to result in an inferior o r poor grade of `plating Work.Generally stated, therefore, the object o the invention is to provide animproved con'- struction and an improved method or proc# ess whereby theelectroplating solution is drawn from the tank or other receptacle, .bysuction produced b a jet of compressed air, or by other suitab e means,and is then filtered and returned to the ltank or other receptacle, byfiltration means of any suitable character, thus continuouslyeliminating the foreign matter or impurities from the solution, andensuring better results in the work of electroplating various objects,as will hereinafter more fully appear.

It is also an object to provide certain details and'features ofimprovement tending to increase the general efliciency and desirabilityof an electroplating 'process or method of this particular character. l

To this and'other useful ends the'invention consists in mattershereinafter setv forth and claimed and-shownin the accompanying drawingsin which Figure 1 is a perspective of an electrop1at ing apparatushaving filtration means embodying the principlesof the invention.

Figure 2 is an enlarged detail sectional View of a portion of saidfiltration means.

As thus illustrated, the invention comprises a tank l, or a receptacleof any suitvable or desired character, in which the electroplating.solution is held. Said solution,

of course, may be of any suitable or desired character, depending uponthe character of the Work to be done. For the purpose of continuouslyfiltering the solution, an intake pipe 2 having openings 3 in the sidesthere- 'of is arranged to extend along the bottom of the tank, and isprovided with an upwardly extending portion 4 which is coupled at itsupper end to the base 5 of the filf tration means, said base beingsecured to the tank or any sultable support in any suitable or desiredmanner. The solution is sucked 'in through the openings 3, bythe air jetdischarged upwardly 'in the pipe 4 from the small comressed air pipe 6,and is discharged /from the top of the pipe 4 into the hollow head 7 ofsaid filtration means, and from said head vinto the vfilter bag 8, whichlatter may be of any suitable or desired material, depending upon thechavacter of the solution; There 'are well known materials which are notattacked by the various solutions employed =in electroplating, and anyof these materials may be used for this purpose, themeshes of the headbeing fine enough to prevent dirt and4 sediment and other foreign matterfrom passing through, but being open enough to permit the sc lutionitself to flow-through easily and back into the tank. This filter bag isremovably attached to the bag at 9 by a screw connection of any suitablecharacter, or in any suitable or desired manner. The compressed air issupplied to the pipe 6 from a main pressure pipe 10 through a lvalve 11by which the force of the upwardly directed jet from pipe 4 may becontrolled at will, and whereby the jet may be shut'ofl entirely whensuch is necessary or desirable. It is desirable to eliminate the Yairfrom the solution, before the latter passes into the filter bag 8, andthis may be done in various Ways. 'For example, a hollow trap 12 may beprovided to extend upf wardly. on the base 5, into which theK air fromthe solution will pass and beheld, while the solution thus segregatedfrom the air will then pass through the head 7 and into the filter bag.A small relief valve 13, or outlet of any suitable character, may beprovided on one side of the air trap 12 to permit the escape of the airin a manner that will not create too much back pres-I sure, but onlyenough to keep the solution from rising in the trap 12, thereb to compelthe solution to pass in the ot er direction. and enter the filter bag.rlhe dirt or impurities or foreign matter will naturally settle, more orless, to the bottom of the tank, and it will be sucked into the openings3 with the liquid solution, and will be caught and held by the bag 8,which latter can be cleaned from time to time in order to dispose of theaccumulation of dirt and foreign substance therein. Thus the solution isfiltered' afterit is forcibly drawn or sucked from the tank and beforeit is again discharged vinto the top of the tank in'purified form,having been filtered and thereby reduced to a better condition lfor usein the electroplating work. Gradually, therefore, dirt and impuritiesand precipitates and other foreign substances are eliminated from thesolution, so that the electroplating work may proceed with highereiciency, and with better results, and with less liability of blemishesor disy colorations or pinholes or other defects on the surface of thework. A 'further beneficial action is obtained by agitation of thesolution, and this is preferably done by bubbling the solution, or byaeration, so to speak, so that the solution `is maintained in anagitated condition which not only produces certain beneficial e'ectsheretofore obtained by agitation, but it also renders the filtrationapparatus more eRective. F or example, outlets l'therein may be placedon the bottom of the tank and'connected with the riser 16, the latterbeing in turn `connected by a valve 17 with the main compressed air pipe10 previously mentioned. `lt .will be .seen that the previouslymentioned pipe 2 is arranged to rest on the pipe 14, and with thisarrangement rair is forceqd down through the pipe 16' and into the` pipe14 and outthrough the openings 15 into the solution, thereby causing abubbling action,

` resulting in the j. desired agitationl of the solution, and aerationof the liquid. -Thus air agitation is combinedl with ltration of thesolution, in the manner shown and. described, so that the work not onlyhas the advantage of the agitation-to ensure better results, but alsothe beneficial action resulting from lthe filtration of the solution.The filtering action is facilitated bythe agita-l tion, as vthe airinjected into the solution stirs up the sediment or foreign matter. andin. this way the solution with the. foreigna zigzag pipe14 havingthereof in the tank;

valve 13 is closed enough, the

matter in suspension passes through the openings 3 previously mentionedand into the pipe 2 and then up and into the filter in the mannerexplained. lit is true, therefore, that not only is the solutionfiltered in this manner, by lifting or drawing the solution upward bymeans of an air jet, but also that the solution is agitated by airduring the circulation and filtering of the solution. Again, as a matterof still further and special improvement, .in conjunction with thefiltration of the solution, a vertically disposed reservoir 18 isprovided for the head 7, in position to 4discharge downwardly toward thefilter bag 8, in the manner shown in Figure 2 of theydrawings. For thispurpose a fine wire mesh strainer 19 is provided at the top of thefilter bag to receive the discharge from the reservoir or magazine 18,it being understood that this tubular magazine 18 is provided at itsupper end `'with a removable cover 19 to' permit the lling of the tubewith any suitable or desired substance, depending upon the chemicalaction to be obtained. rlhe salts 20, or other substance, feed graduallydownwardin the magazine 18 and rest upon the strainer 19 in position tointercept the solution as the latter flows from the head 7 into thefilter bag. In other words, the solution must pass throughl the salts orother substance 20 before it can enter the filter bag, and in this waythe solution can be subjected to any desired or beneficial actiontinuously subjected tofour things, succes-4 sively as follows: First,the air agitation second, the raising or drawing of the agitatedsolution upward by the jet of the solution, after the air is freedtherefrom, by the salts or other substance 20 in the magazine 18 asstated; and fourth, the ltering of the solution by the filter bag 8before it is' discharged by gravity on to the upper surface of the bodyof the solution in the tank. All this, of course, tends to ensure betterres lts in the .work of metal plating any suitabh may be immersed in thesolution, and en- 1si'ireis against blemishes or defects of other positof such object. .The relief valve 13 has a pipe 21 which extends pwardin the air trap 12 to a point near the top of the latter, so that thesolution canrise quite a distance therein before it overfiows into thepipe and out through said valve., lf the air pressure in the topy of thetrap will prevent the solution from rising very much air; third, theinterception of` l e or desired object which s on the surface of themetallic dev therein, as

might be the situation for some purposes; but for other kindsvof workthe relief valve 13 will be wide open -to prevent any back pressure ofthe air, and the solution will overflow through the pipe 21 if it doesnot lflow fast enough through the filter bag, as might be the case ifthe latter becomes clogged to some extent. It is understood, of course,that the apparatus shown and described is merely illustrative of theinvention, for the invention in its broader aspects is not limited toany particular form of a paratus.

Vifliat I claim as my invention is 1. In a process of electroplating,the.

tion and force it upward to said point where it is filtered and returnedto the body of the solution.

3. A process as specified in claim 1, including the use of air pressureto circulate the solution upward to said point of filtration thereof,and the elimination of the air from the solution before said point offiltration is reached.y

'4. A process as specified in claim 1, comprising the use of a jet ofair to suck the solution into the path of circulation and to force thesame upward to the point of filtration thereof, and releasing the airfrom the circulating portion of the solution before it reaches saidpoint of filtration, so that the released air escapes in one directionwhile the solution is filtered and allowed to return by gravity inpurified condition to the said main body of the solution.

5. The process as specified in claim 1, comprising in addition theagitation of the main body of the solution to facilitate the gradualelimination of the impurities or foreign matter by said circulation andfiltration of the solution.

6. A process as specified inv claim 1, in-

cluding also the agitation and the bubbling of the main body of thesolution by jets of air at the bottom thereof, whereby the solution isaerated and agitated before v`being raised to point of filtrationthereof.

7. A process as specified in claim 1, including the passage of thecirculating solution through any desired substance before reaching thepoint of filtration" thereof,

whereby 'to produce the desired chemical effect on the solution beforebeingvfiltered.

8. A process as'specified in claim 1, in'

cluding the automatic feeding of soluble salts into the path of thecirculating solution, before the solution reaches the point offiltration thereof, thereby to produce the desired eect.

9. In electroplating apparatus, the combination of a receptacle to holdthe main body of the electroplating solution, means to circulate thesolution from the body thereof and then upward to a point over the bodyof the solution, means to filter the solution before it is returned bygravity to the .top of the solution in the said receptacle, and meansfor forming a jet of air in the path of circulation of the solution toraise the latter tosaid point of filtration thereof.

10. Apparatus as specified in claim 9, comprising means to release theair from the solution before the latter reaches said point of filtrationthereof.

11. Apparatus as specified in claim 9, comprising a reservoir forautomatically'feeding any desired substance into the path of thesolution before' the latter reaches the point of filtration thereof.

12. Apparatus as specified in claim 9, in combination with means forusing air to agitate the mainv body of the solution.

13. In a process of electroplating, the circulation of theelectroplating solution from the body thereof to a point above the bodyof the solution and the filtering of the solu- A tion thus drawnofilbefore it is discharged on to the top of the body of said solution,

comprising the use of a jet of air to suck the solution into the path ofcirculation and to force' the same upward to the point of filtrationthereof, and releasing the air from the circulating portion of thesolution before it reaches said point of filtration, so that thereleased air escapes in one direction while the solution is filtered andallowed to return by gravity in purified condition to the said main bodyof the solution, including also the agitation and the bubbling of themain body of the solution by jets of air at the bottom thereof, wherebythe solution is aerated and' agitated before being raised to the pointof filtration thereof.

14. A process as' specified in claim 13,'iin-` cluding the passage ofthe circulating solution through any desired substance before reachingthe point of filtration thereof, whereby to produce the desired chemicalef; fect on the solution before being filtered.

WILLIAM E. .BELKE

